Despite how attractive cloud computing can sound as an outsourcing option, there's widespread concern that it presents a security and legal minefield for businesses and government. Cloud service providers often cultivate an aura of secrecy about data centers and operations, claiming this stance improves their security even if it leaves everyone else in the dark

Perhaps it's just very difficult to determine where particular files are stored. Or perhaps it's an unanswerable question.

Providers such as Google and Amazon have numerous datacenters. Storage undoubtedly involves redundancy and striping, and perhaps more elaborate schemes involving encryption, with components that may be geographically-distributed. And then there's load balancing, and backups.